I'm trying to figure out if my 161,000 mile 325Ci's TCC behavior is normal or if I should be worried.

I've always been greatly annoyed at the TCC in this car. It's always locking and unlocking. It's hyper.

But what I've noticed is that when just cruising along at 65 mph is that I'm hearing fluctuations in engine RPM, and I see it on the tach. It's always up and down 50-100 revs, even with constant throttle pressure.

Should I do a fluid and filter swap? I did one when I bought the car at 133k. The filter was in rough shape and the fluid was dirty but not awful.

I haven't scanned lately, but I haven't gotten any codes. Is this just normal?